Chromosome Location, Linkage with Simple Sequence Repeat Markers, and Leaf Rust Resistance Conditioned by Gene Lr63 in Wheat

RL6137, a ‘Thatcher’ backcross line of wheat (Triticum aestivum L.) has resistance to Puccinia triticina (causal agent of wheat leaf rust) derived from T. monococcum. To determine the chromosome location of this resistance, RL6137 was crossed with Thatcher and F2 individual seedlings were tested for segregation of leaf rust resistance and segregation of polymorphic simple sequence repeat (SSR) markers. Leaf rust resistance genotypes of F2 individuals were confi rmed with segregation of F3 families. The F2 seedlings and F3 families segregated for a single leaf rust resistance gene. The SSR markers barc 57 and barc 321 located on chromosome 3AS were tightly linked with the leaf rust resistance gene. The leaf rust resistance gene in RL6137 was designated as Lr63. This gene conditions low to intermediate infection types to most P. triticina isolates and can be used in wheat improvement programs to enhance leaf rust resistance. J. A. Kolmer, USDA-ARS Cereal Disease Laboratory, St. Paul MN, 55108; J. A. Anderson, Dep. of Agronomy and Plant Genetics, University of Minnesota, St. Paul MN, 55108; J. M. Flor, Dep. of Plant Pathology, University of Minnesota, St. Paul, 55108. Received 4 Jan. 2010. *Corresponding author ( [email protected]). Abbreviations: IT, infection type; SSR, simple sequence repeat. Published in Crop Sci. 50:2392–2395 (2010). doi: 10.2135/cropsci2010.01.0005 Published online 27 Sept. 2010. © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher.